The promise of nanotechnology lies in how new nanostructured materials react to and guide heat, light, charge, or molecular species. The design of nanomaterials with tailored transport properties—even unusual ones not found in nature, such as "metamaterials" that have negative refractive indices—are the foundation of new technologies for a broad range of applications, including energy production and storage, separations, and catalysis.

Sophisticated nanoscale structures can be manufactured from the "top down." The fabrication processes of repeated etching and deposition of semiconductors, metals and dielectrics gives us complex and powerful integrated circuits. But nanoscale structures can also be created from the "bottom-up", wherein a milieu of building blocks in a dispersed, homogeneous state is cast, printed, or deposited. From this precursor jumble, functional nanomaterials spontaneously form by self-assembly as the building blocks arrange into coherent nanoscale structures dictated by their thermodynamics. This bottom-up approach to nanomanufacture promises low-cost and high-rate continuous processes.

In this talk, I will focus on colloidal and nanoparticle self-assembly using directing fields. While thermodynamics dictates the structures that form by self-assembly, the kinetics of colloidal self-assembly are often trapped into arrested states, such as glasses and gels. Kinetic bottlenecks are circumvented using electric and magnetic fields to guide the assembly, while retaining the strengths of a “bottom-up” self-assembly process.

physics and chemistry of colloidal, polymeric, biomolecular, and other soft materials. The engineering applications of our work include materials for energy conversion, structured and complex fluids, nanotechnology, and biotechnology.